Here he found himself a good deal below the level of the car.  These sleepers have no foot-boards like ordinary carriages; access to them is gained from a platform by the steps at each end.  The Chief was short of stature, and he could only approach the window outside by calling one of the guards and ordering him to make the small ladder (faire la petite echelle).  This meant stooping and giving a back, on which little M. Flocon climbed nimbly, and so was raised to the necessary height.

A close scrutiny revealed nothing unusual.  The exterior of the car was encrusted with the mud and dust gathered in the journey, none of which appeared to have been disturbed.

M. Flocon reentered the carriage neither disappointed nor pleased; his mind was in an open state, ready to receive any impressions, and as yet only one that was at all clear and distinct was borne in on him.

This was the presence of the lace and the jet beads in the theatre of the crime.  The inference was fair and simple.  He came logically and surely to this: 

1.  That some woman had entered the compartment.

2.  That whether or not she had come in before the crime, she was there after the window had been opened, which was not done by the murdered man.

3.  That she had leaned out, or partly passed out, of the window at some time or other, as the scrap of lace testified.

4.  Why had she leaned out?  To seek some means of exit or escape, of course.

But escape from whom? from what?  The murderer?  Then she must know him, and unless an accomplice (if so, why run from him?), she would give up her knowledge on compulsion, if not voluntarily, as seemed doubtful, seeing she (his suspicions were consolidating) had not done so already.

But there might be another even stronger reason to attempt escape at such imminent risk as leaving an express train at full speed.  To escape from her own act and the consequences it must entail—­escape from horror first, from detection next, and then from arrest and punishment.

All this would imperiously impel even a weak woman to face the worst peril, to look out, lean out, even try the terrible but impossible feat of climbing out of the car.

So M. Flocon, by fair process of reasoning, reached a point which incriminated one woman, the only woman possible, and that was the titled, high-bred lady who called herself the Contessa di Castagneto.

This conclusion gave a definite direction to further search.  Consulting the rough plan which he had constructed to take the place of the missing train card, he entered the compartment which the Countess had occupied, and which was actually next door.

It was in the tumbled, untidy condition of a sleeping-place but just vacated.  The sex and quality of its recent occupant were plainly apparent in the goods and chattels lying about, the property and possessions of a delicate, well-bred woman of the world, things still left as she had used them last—­rugs still unrolled, a pair of easy-slippers on the floor, the sponge in its waterproof bag on the bed, brushes, bottles, button-hook, hand-glass, many things belonging to the dressing-bag, not yet returned to that receptacle.  The maid was no doubt to have attended to all these, but as she had not come, they remained unpacked and strewn about in some disorder.